Preclinical Evaluation of CAR Treg Therapy for Targeted Immunosuppression in Atherosclerosis

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Summary of  Circulation https://doi.org/10.1161/CIRCULATIONAHA.125.073987 
Dr. Robert D. Schwab  et al.

Points

Researchers engineered regulatory T cells to target oxidized LDL and suppress the specific inflammatory pathways that drive the accumulation of atherosclerotic plaque in the arteries.
The study utilized immunocompetent mouse models predisposed to high cholesterol to evaluate the preventive efficacy of the therapy over a twelve-week treatment period.
Assessment of the murine hearts and aortas revealed that the treatment successfully reduced the burden of atherosclerotic plaque by approximately seventy percent compared to controls.
In vitro experiments confirmed that these engineered cells inhibit macrophage foam-cell formation through cytokine-mediated immunosuppression without disrupting the general immune function of the subjects.
This targeted approach suggests a novel method for treating the underlying inflammation of heart disease in patients who retain high risk despite standard lipid-lowering therapies.

Summary

This study investigated the efficacy of utilizing chimeric antigen receptor (CAR) regulatory T cells (Tregs) to treat atherosclerosis by targeting oxidized low-density lipoprotein (OxLDL). While traditional CAR T therapies utilize cytotoxic mechanisms to eliminate cancer, this approach engineered Tregs to recognize OxLDL and dampen the specific inflammatory response driving plaque pathogenesis. The researchers utilized an inducible anti-OxLDL CAR Treg platform to evaluate whether targeted immunosuppression could inhibit macrophage foam-cell formation and reduce arterial obstruction without compromising systemic immune function.

The therapeutic potential was assessed using immunocompetent mice genetically predisposed to hyperlipidemia and atherosclerosis. Following a treatment duration of approximately twelve weeks, the cohort receiving anti-OxLDL CAR Tregs demonstrated a marked reduction in disease progression. Analysis of the murine hearts and aortas revealed a nearly 70% reduction in atherosclerotic plaque burden compared to the untreated control group. In vitro assays corroborated these findings, showing that the engineered cells significantly suppressed foam-cell accumulation through cell- and cytokine-mediated mechanisms.

These preclinical results suggest that targeting the inflammatory microenvironment within the arterial wall is a feasible strategy for managing cardiovascular disease. Unlike broad anti-inflammatory agents, the CAR Treg modality localizes immune regulation to the site of plaque development. The findings indicate that this therapy could serve as a complementary option for patients who maintain a high residual risk of ischemic events despite adherence to standard lipid-lowering regimens.

Link to the article: https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.125.073987

References

Schwab, R. D., Degaramo, D., Hong, S. J., Bi, X., Faruqi, A., Aguilar, W., Brookens, S. K., Keane, J. T., Liu, F., Musunuru, K., Rader, D. J., & Posey, Jr., A. D. (2025). Oxldl-targeted chimeric antigen receptor t regulatory cells reduce atherosclerotic plaque development. Circulation, CIRCULATIONAHA.125.073987. https://doi.org/10.1161/CIRCULATIONAHA.125.073987